Tabulations

 History categories

• h1 an account is given since it was found and left the ground.
• h2 known at a date up to 1914.
• h3 known in the period 1915-1944.
• h4 known in the period 1945-1973.
• h5 known in the period 1974-1986.
• h6 known in the period 1987 onwards.
• h7 surfaced on this occasion.
• h8 date of surfacing not known to us.
• h9 date of surfacing uncertain.